Flush ferrule conductor joint



Nov. 8, 1960 D. A. VINEBERG ETAL 2,958,929 FLUSH FERRULE CONDUCTOR JOINT Filed June 1, 1959 1Q I l /2 /3 1a INVENTORS D. A. V/NEBERG 7'. A. MESSEI? Arron/( ns United States Patent 2,958,929 FLUSH FERRULE CONDUCTOR JOINT David Albert Vineberg, Willowdale, Ontario, and Thomas Archibald Messer, Toronto, Ontario, Canada, assignors to Canada Wire and Cable Company Limited, Toronto, Ontario, Canada, a corporation Filed June 1, 1959, Ser. No. 817,359 4 Claims. (Cl. 29155.55)

This invention relates to a method of joining the ends of two electrical conductors and more particularly to a method which compresses both the conductors to be joined and the connecting ferrule so that the outside diameters of both the former and the latter are equal.

The electrical conductors referred to are of the hollow, segmented type consisting of a plurality of solid strips in edgewise contact, each forming a segment of the wall of a semi-flexible tube.

In the prior art there are many types of electrical connectors utilising the compression of a ferrule but the outside diameter of the ferrule remains appreciably greater than that of the conductors, thus upsetting the electrical characteristics of the cable; also the method of compressing and fitting a ferrule would appreciably distort the hollow segmented conductor. for which this method was designed.

The principal object of this invention is to provide an eflicient joint for electrical conductors which will not change the electrical characteristics of the conductors.

Other objects are to provide a connector which is the same outside diameter as the conductors to be joined, one which requires no heat or jointing compound combined with ease of installation.

.These and other objects and advantages will be evident to one skilled in the art upon reading the following description in conjunction with the accompanying drawings, in which:

Figure 1 is a longitudinal cross section of one end of the conductor, at the beginning of the operation, showing the die press in position and the center support bushing and sleeve in place.

Figure 2 is a cross section 2-2.

Figure 3 shows the components of Figure 1 after the die press has been closed and the conductor ends compressed.

Figure 4 is a cross section of Figure 3 taken at line 4-4 and illustrating the ears formed by excess material on the sleeve.

Figure 5 is a longitudinal cross section of both ends of the conductors with the permanent ferrule in place and the die press positioned prior to the permanent join being effected.

Figure 6 is a cross section of Figure 5 taken at line 6-6.

Figure 7 is a longitudinal cross section of the components in Figure 5 after the die press has been closed and the conductor ends and ferrule compressed.

Figure 8 is a cross section of Figure 7 showing slight flashing of the ferrule prior to its final clean up.

In Figure 1 an electrical conductor 10 of annular cross section and of conventional segmented form is supported internally by a hollow bushing 11.

The bushing 11 is of cylindrical form and a close fit in the bore of conductor 10; it is waisted for a substantial part of its length leaving an annular space 12 beof Figure 1 taken at line tween the waisted portion 13 and the inner surface "14 of conductor 10. An integral circular flanged portion 15 is of slightly larger diameter than the bore of conductor 10 thus acting as a stop to position bushing 11 accurately in conductor 10.

A sleeve 16 of annular cross section is slidably fitted over the conductor 10 to a predetermined distance, which is slightly less than the distance which the waisted portion 13 of bushing 11 extends into the bore of conductor 10.

A die press 17 of conventional design is fitted around the sleeve 16, the interior being cylindrical. It is divided into an upper half 18 and a lower half 19 and when in facial contact the diametrically opposed edges 20 and 21 are relieved by longitudinal channels 23 and 24 of triangular cross section. The internal diameter of die press 17 is equal to the external diameter of conductor 10.

In Figure 3, die press 17 has been closed as far as possible and, through sleeve 16, conductor 10 has been squeezed into the annular space 12 and is now in full contact with bushing 11. At the same time, sleeve 16, having been forced to a smaller diameter, has extruded into the longitudinal channels 23 and 24 to form a pair of diametrically opposed ears 25 and 26 (see Figure 4) which extend the length of the sleeve 16.

In Figure 4 it can be seen that each of the ears 25 and 26 consists of a double thickness of the wall of sleeve 16, so that when the ears 25 and 26 are removed by cutting through the ears along lines tangential to the surface of the sleeve, the sleeve 16 will split into two semi-cylindrical halves and is then easily removed from the conductor 10.

It may readily be seen that the foregoing process may be applied to one end of the conductor 10 at a time or to two ends in abutment.

In Figure 5 the conductor 10 is slidably inserted into the bore of a ferrule 32. Ferrule 32 has countersunk ends 33 and 34 to match the configuration of the narrow compressed conductor end 10. Similarly, a conductor 27 which has undergone the same process as conductor 10 and is in full contact with a bushing 28, is slidably inserted into the other end of ferrule 32, flanged portion 15 of bushing 11 being in facial contact with a corresponding flanged portion 31 of bushing 28.

Figure 7 illustrates the action of the device when die press 17 is fully compressed. Ferrule 32 has transmitted the pressure to conductors 10 and 27. Bushings 11 and 28 being virtually unaffected by pressure, the conductors 10 and 27 are forced to expand longitudinally, this will cause each to move outwardly slightly and, in turn, bushings 11 and 28 will move apart. Ferrule 32 will compress further until it comes into contact with flanged portions 15 and 31, at which time it will be of the same external diameter as the uncompressed portions of conductors 10 and 27 and will be in highly compressive contact with the end portions of conductors 10 and 27.

As illustrated in Figure 8 a slight amount of flashing 35 and 36 will occur at the diametrically opposed edges 20 and 21 but this may be cleaned up with no detrimental eiIect on the strength of the ferrule 32.

What we claim as our invention is:

l. The method of fitting a ferrule to the end of an electrical conductor of' circular cross section, for the external diameter of the ferrule to be equal to the external diameter of the conductor, comprising the steps of applying a sleeve over the end of the conductor, compressing the sleeve and conductor to reduce their external diameters while preserving the circular cross section of the conductor, the sleeve during compression 3, being caused to buckle radially outwardly of the conductor along two diametrically opposed lines to form a pair of diametrically opposed ears extending along the sleeve parallel to its longitudinal axis, each car being composed of a double trickness of the sleeve- Wall, removing the sleeve, by cutting through the ears along lines tangential to the surface of the sleeve to separate the sleeve into two halves, applying the ferrule over the compressed end of the conductor, the ferrule having an internal diameter equal to the external diameter of the compressed end of the conductor and an external diameter greater than the external diameter of the uncompressed conductor and then further compressing the ferrule and conductor end until the external diameter of the ferrule equals the external diameter of the uncompressed conductor.

2. The method of fitting a ferrule to the end of a hollow electrical conductor of annular cross section, for the external diameter of the ferrule to be equal to the external diameter of the conductor, comprising the steps of supporting the interior of the conductor against internal collapse, applying a sleeve over the end of the conductor, compressing the sleeve and conductor to reduce their external diameters while preserving the annular cross section of the conductor, the sleeve, during compression, being caused to buckle radially outwardly of the conductor along two diametrically opposed lines to form a pair of diametrically opposed ears extending parallel to'the longitudinal axis of the sleeve, each ear being composed of a double thickness of the sleeve wall, removing the sleeve by cutting through the ears along lines tangential to the surface of the sleeve to separate the sleeve into two halves, applying the ferrule over the compressed end of the conductor, the ferrule having an internal diameter equal to the external diameter of the compressed end of the conductor and an external diameter greater than the external diameter of the uncompressed conductor and then further compressing the ferrule and conductor end until the external diameter of the ferrule equals the external diameter of the uncompressed conductor.

3. The method of joining, by means of a ferrule, abutting end portions of adjacent electrical conductors of circular cross section and having equal diameters, for

the external diameter of the joint to be equal to the external diameters of the conductors, comprising the steps of applying a sleeve over the ends of the conductors, compressing the sleeve and the conductors to reduce their external diameters while preserving the circular cross sections of the conductors, the sleeve during compression being caused to buckle radially outwardly of the conductors along 'two directly opposed lines to form a pair of diametrically opposed ears extending along the sleeve parallel to its longitudinal axis, each ear being composed of a double thickness of the sleeve wall, removing the sleeve, by cutting through the ears along lines tangential to the surface of the sleeve to separate the sleeve into two halves, applying the ferrule over the compressed ends of the conductors, the ferrule having an internal diameter equal to the external diameters of the compressed ends of the conductors and an external diameter greater than the external diameters of the uncompressed conductors and then further compressing the ferrule and ends of the conductors until the external diameter of the ferrule equals the external diameters of the uncompressed conductors.

4. The method of joining, by means of a ferrule, abutting end portions of adjacent hollow electrical conductors of annular cross section and having equal external diameters, for the external diameter of the joint to be equal to the external diameters of the conductors, comprising the steps of supporting the interior of each conductor against internal collapse by means of bushings, one inserted within each hollow conductor, applying a sleeve over the ends of the conductors, compressing the sleeve and the conductors to reduce their external diameters while preserving the annular cross section of the conductors, the sleeve, during compression, being caused to buckle radially outwardly of the conductor along two diametrically opposed lines to form a pair of diametrically opposed ears extending parallel to the longitudinal axis of the sleeve, each ear being composed of a double thickness of the sleeve wall, removing the sleeve, by cutting through the ears along lines tangential to the surface of the sleeve to separate the sleeve into two halves, applying the ferrule over the compressed ends of the conductors, the ferrule having an internal diameter equal to the external diameters of the compressed ends of the conductors and an external diameter greater than the external diameters of the uncompressed conductors and then further compressing the ferrule and conductor ends until the external diameter of the ferrule equals the external diameters of the uncompressed conductors.

References Cited in the file of this patent UNITED STATES PATENTS 376,780 Murphy Jan. 24, 1888 461,868 Fleming Oct. 27, 1891 470,623 Levez Mar. 8, 1892 879,631 Gregson Feb. 18, 1908 7 910,684 Horner Jan. 26, 1909 1,245,596 Kirk Nov. 6, 1917 1,727,895 Mraz Sept. 10, 1929 2,102,325 Kylstra Dec. 14, 1937 2,113,228 Bassett et al. Apr. 5, 1938 2,132,555 Baxter Oct. 11, 1938 2,375,574 -Netheny et a1. May 8, 1945 2,516,930 Variau Aug. 1, 1950 FOREIGN PATENTS 775,557 Great Britain c-.." May 29, 1957 

